| Project/Area Number |
63550347
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
コンクリート工学・土木材料・施工
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| Research Institution | Akita University |
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Principal Investigator |
TOKUDA Hiroshi Akita University, Mining College, Professor, 鉱山学部, 教授 (70041879)
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| Co-Investigator(Kenkyū-buntansha) |
KAGAYA Makoto Akita University, Mining College, Research Associate, 鉱山学部, 助手 (00091794)
KAWAKAMI Makoto Akita University, Mining College, Associate Professor, 鉱山学部, 助教授 (90006693)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1989: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1988: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Extremely Stiff Consistency Concrete / Compaction Degree / Cement Paste Pressure / Compressive Strength / 締固め度の判定 / 圧縮強度 / 超硬練りコンクリート / 振動機特性 |
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| Research Abstract |
The extremely stiff consistency and lean six concrete was placed into prismatic specimen moulds and compacted by surface vibrator. The compaction process was observed through a transparent side panel of the mould and the cement paste pressure was measured simultaneously by pore water pressure gauge embedded in the bottom part. On the other hand, unit contents of internal constituent materials and compressive strength in each position in the vertical direction were measured. The conclusions are as follows.
(1) Cement paste moved downward at early compaction stage, subsequently the moving direction changed to upward and spaces between aggregate particles were filled up thoroughly by cement paste.
(2) The pressure in cement paste increased gradually with compaction periods and reached the maximum value just at the time the spaces were filled up, and then turned to decrease.
(3) The air content in each position decreased with increase in compaction periods, and the content in lower position was about 1% higher than that in upper position. Water cement ratio in lower position was higher than that in upper position up to certain compaction periods, and after these periods the reversed trend could be observed.
(4) The periods taking to reach the maximum pressure were nearly equal to those corresponding to the maximum compressive strength. Therefore, compaction degree could be judged by measuring the pressure. Still more, the gauge attached to the end of steel pipe was embedded in the large scaled specimen, and after compaction effort the pipe could be pulled out easily and be reused.
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